hi Jilly and welcome to the forum. I'm sure there will be some very helpful information coming your way soon, however, I can inform that a number of bars and restaurants in Calis have free wifi, some even provide computers, and there is at least one internet cafe in Calis that I know of.
Hope you have a fantastic holiday and I'm sure that, like most of us here, Calis will soon be top of your list of favourite places to visit again and again....